Hypersensitivity to tinzaparin, heparin or Na metabisulfite. Current or history of heparin-associated thrombocytopenia (type II); uncontrolled severe HTN; septic endocarditis; intracranial or intraocular bleeding or other current active bleeding process; haemorrhagic diathesis (inherited or acquired), deficiency of coagulation factors, severe thrombocytopenia; severe liver or pancreas impairment; active gastric &/or duodenal ulcer disease; surgery involving the brain, spinal cord or eye; lumbar puncture, spinal or epidural anaesth; haemorrhagic stroke, cerebral aneurysm; retinopathy, vitreous haemorrhage. Women w/ abortus imminens. Newborns (risk of gasping syndrome due to benzyl alcohol content).